adventitia: endopelvic fascia that connects the vagina to surrounding pelvic structures to maintain support

Embryology

Embryological derivation of the vagina is from two parts, which is important for understanding the origin of congenital anomalies:

upper two-thirds of the vagina, cervix and uterus: all derived from the paired Mullerian / paramesonephric ducts.

lower one-third of the vagina: derived from the bilateral sinovaginal bulbs which arise from the urogenital sinus

Radiographic features

Ultrasound

During transabdominal (TA) scanning the distended bladder, which acts as an acoustic window, does not affect vaginal position. The vagina can, therefore, be used as an effective landmark, even if the uterus does not occupy its familiar position in the pelvis. The vagina is best seen with a midsagittal TA approach, with a partially-filled bladder. The vagina is hypoechoic and the mucosa is echogenic. The echogenicity of the mucosa diminishes in menopause, with the loss of estrogen stimulation.